Control systems and control theory are well-developed fields of research and development that have had a profound impact on the design and development of a large number of systems and technologies, from airplanes, spacecraft, and other vehicle and transportation systems to computer systems, industrial manufacturing and operations facilities, machine tools, process machinery, and consumer devices. Control theory encompasses a large body of practical, system-control-design principles, but is also an important branch of theoretical and applied mathematics. Various different types of controllers are commonly employed in many different application domains, from simple closed-loop feedback controllers to complex, adaptive, state-space and differential-equations-based processor-controlled control systems.
Many modem intelligent controllers include various types of displays, including text and graphical displays and display interfaces that allow text and graphical information to be displayed on any of various local and remote devices interconnected with the intelligent controllers. These displays, as discussed further below, are used for higher-level interactive control-input interfaces and control-schedule interfaces. In addition, many intelligent controllers display continuously, periodically, or intermittently updated information about regions or volumes controlled by the intelligent controllers and information related to control tasks submitted to the intelligent controllers. Designers, developers, manufacturers, and, ultimately, users of intelligent controllers continue to seek new types of information displays and information-display capabilities within, and provided by, intelligent controllers.